The Product
Carbon Footprint
of EU Beet Sugar
«
«
Summary of Key Findings
Sugar Industry Journal, Issue 137 (62) March-April 2012
(by Ingo Klenk, Birgit Landquist and Oscar Ruiz de Imaña)
A
landmark research article recently published provides for the
first time a detailed estimate of the carbon footprint of EU beet
sugar. On that basis, it also compares the carbon footprint of
beet sugar with that of cane sugar as consumed in the EU as well as
starch syrups (isoglucose/ High Fructose Corn Syrup).
This research also ventures beyond product carbon footprints and into
other relevant agro-ecological aspects that should be taken into
account when assessing the overall sustainability of sugar (from cane
or beet) consumed in the EU such as an adequate management of
water resources, an efficient use of available land and the role of
rotational crops in developing a sustainable agriculture.
www.cefs.org
KEY FINDINGS
kgCO2/t sugar
800
■ The carbon footprint of EU beet sugar was found to
vary widely according to different carbon accounting
methodologies. Even though the same data set was used,
the use of different methodologies lead to a wide range of
results for beet sugar (i.e. 242-771 kgCO2eq/t sugar).
600
242-771
400
■ EU Beet sugar carbon footprint
200
(Section 4 of the article on 'The Carbon Footprint of EU Beet Sugar')
1200
■ The carbon footprint range for EU beet sugar was found
to be at least similar, if not lower, than cane sugar imported
and refined in the EU. In the case of starch-based glucose
and fructose syrups (‘isoglucose’ or ‘HFCS’), the available
literature indicated a higher carbon footprint range than
EU beet sugar.
640-1100
1000
kgCO2/t sugar
800
242-771
642-760
600
400
200
(Section 5.1 of the article on 'The Carbon Footprint of EU Beet Sugar')
100
■ In the EU the average distance from beet field
to factory is just 45 km as beet sugar factories
are located in the heart of rural areas.
The transport cycle of raw cane sugar to EU
refineries involves greater distances. Overall,
transport and refining represents approximately
45-61% of the total emissions of cane sugar
consumed in the EU.
(Section 5.1.1 of the article on 'The Carbon Footprint of EU Beet Sugar')
CANE
MILL
0
45 km
is the average
distance from
beet field to
factory in
the EU
Cane
sugar
transport
Cane
sugar
refining
14-23%
32-38%
RAW SUGAR
■ Emissions due to direct land use change (dLUC) result from using previously
uncultivated land, rich in CO2 (e.g. forests). EU sugar beet is grown in existing
agricultural land and therefore dLUC emissions are deemed to be negligible.
Studies on cane sugar generally do not account for those emissions although
they can result in a carbon footprint that is five times higher!
(Section 2.1 of the article on 'The Carbon Footprint of EU Beet Sugar')
REFINERY
EU beet
sugar dLUC
emissions
are virtually
zero!
LAND
USE EFFICIENCY
50% less land is required
by beet systems compared
to cane in order to produce
an equivalent amount of
products with equivalent
greenhouse gas
emissions
(Sections 3.3 and 5.2
of the article)
WATER
REQUIREMENTS
Sugar beet cultivation
requires 50% less
water than sugar
cane.
(Section 7 of the article)
CROP ROTATION BENEFITS
Sugar beet is a rotational crop. It is only
grown in the same field once in every three to five
years and is never grown for continuous monoculture
unlike sugar cane which is generally grown on the same field
for a period of three to five years. As root crop, sugar beet plays a
key role in breaking up the common cereal-based crop rotations.
The cereal yield after beet is 10-20% higher than after two
successive years of cereals. Because sugar beet is not a host to pests
or diseases which generally affect combinable crops, the cultivation
of sugar beet reduces the level of weeds, diseases and pests and
therefore reduces the amount of pesticides applied at farm
level. Once emerged, sugar beet is less vulnerable to
climatic variations than other crops. This relatively
low year-to-year variability facilitates
farm input management.
(Section 7 of the article & CIBE-CEFS Environmental
Sustainability report (2010)
A short note on Methodologies:
The product carbon footprint of EU beet sugar was calculated
using a “cradle to gate” assessment. System limits were
from the cultivation of the sugar beet up to and including the
sugar factory.
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The greenhouse gas emissions of the entire system were
identified and calculated using the stepwise procedure as
defined in the ISO standard 14044 for emissions accounting.
From Field to Sugar Factory: the Life Cycle of EU Beet Sugar
Photosynthesis
Rainfall
CO2 O2
Irrigation
Evapotranspiration
H2O
Sunlight
Seed
Plant protection
Organic & Mineral Fertiliser
Machinery operations
SUGAR BEET
Sampling
Fuel
Weighing
Lime kiln
Unloading / storage
Limestone
Milk
of
lime
tank
Diffusion
Cleaning
Slicing
Electricity
Power station
2
Lime
Purification
Steam
Evaporation
Water (treated)
Low temperature heat
Clarify & filter
Filter
Beet tops and tails
Pulp press &
drying
Wash & screen
Thick juice storage
Crystallisation
Stones
Dry screen & mix
Fermentation
& distillation
Silos
Biogas
Animal feed
Lime fertiliser
Bioethanol
Vinasse
Sugar products
s
Screen &
pack
Construction
Separation
Molasse
Pelleting
Fermenters
Soil & compost
River
Evaporation
Fermentation products
District heating
Electricity
Source: CIBE and CEFS (after British Sugar)
CEFS, founded in 1953,
represents all European beet
sugar manufacturers and
cane sugar refiners,
covering sugar production
in 20 EU countries (Austria,
Bulgaria, Belgium,
the Czech Republic,
Denmark, Finland, France,
Germany, Greece, Hungary,
Italy, Lithuania, Portugal,
Romania, the Netherlands,
Poland, Slovakia, Spain,
Sweden and the United
Kingdom) plus Switzerland.
CEFS
Comité Européen
des Fabricants de Sucre
Avenue de Tervuren 182
B-1150 Brussels
Tel: + 32 (0) 2 762 07 60
Fax: + 32 (0) 2 771 00 26
[email protected]
www.cefs.org
Sugar beet area
Beet sugar factory
Beet ethanol factory
Cane sugar refinery
Combined beet & cane sugar refinery
La Réunion Guadeloupe Martinique
137 (62) March 2012
A 7471 E
3
The Product Carbon Footprint of EU beet sugar
by Ingo Klenk, Birgit Landquist and Oscar Ruiz de Imaña
Reprint from SUGAR INDUSTRY / ZUCKERINDUSTRIE 137 (2012) No. 3, 169–177, and No. 4
Verlag Dr. Albert Bartens, Berlin, Germany
Bartens
Technology/Technologie
Ingo Klenk, Birgit Landquist, Oscar Ruiz de Imaña
The Product Carbon Footprint of EU beet sugar
Die Treibhausgasbilanz von EU-Rübenzucker
The calculations made to obtain the PCF of EU white
sugar from sugar beet have revealed that the results are
extremely sensitive to methodological choices and this
article provides some recommendations in that regard.
A comparison of EU beet sugar with two examples of raw
cane sugar imported and refined in the EU, showed that
the PCF range for EU refined cane sugar is on average similar, if not higher (642–760 kg CO2eq/t sugar) than the total
methodological PCF range for the EU beet sugar average
case (242–771 kg CO2eq/t sugar). A review of the published
literature revealed, on the one hand, that land use change
emissions for cane sugar can be very significant but are
rarely taken into account, and on the other hand, that
overseas transport and refining adds a significant amount
of emissions to the PCF of raw cane sugar imported into
the EU. An overall land use efficiency comparison between
cane and beet production systems also concluded that
significantly more land (51%) is required by cane systems
to produce an equivalent set of products (sugar and coproducts) with an equivalent amount of GHG emissions.
Finally, the limitations of PCFs as a tool to evaluate the
overall environmental sustainability of EU beet sugar were
also analysed.
Berechnungen der Treibhausgasbilanz (bzw. Product Carbon
Footprint PCF) von EU-Weißzucker aus Zuckerrüben ergaben,
dass das Ergebnis sehr stark durch die Wahl der Methodik beeinlusst wird. Dieser Artikel enthält daher diesbezügliche Methodikempfehlungen. Der PCF von EU-Rübenzucker (Mittelwert)
wurde mit zwei Beispielen für importiertem und in der EU rainierten Rohrohzucker verglichen. Es zeigte sich, dass der PCF von
importiertem rainierten Rohrzucker im Durchschnitt vergleichbar, wenn nicht sogar höher ist (642–760 kg CO2eq/t Zucker) als
die methodisch bedingte, vollständige Ergebnisbandbreite im
Falle von EU-Rübenzucker (242–771 kg CO2eq/t Zucker). Eine
Auswertung von Veröfentlichungen zum Betref zeigte einerseits, dass für Zuckerrohr Emissionen aus Landnutzungsänderungen erheblich sein können, jedoch selten berücksichtigt
werden; andererseits, dass Überseetransporte und Raination
signiikante Anteile am PCF von in die EU importierten Rohrrohzucker haben. Aus einem Vergleich der Flächennutzungseizienz von Produktionssystemen auf Basis von Zuckerrohr bzw.
Zuckerüben konnte gefolgert werden, dass der Flächenbedarf von
Produktionssystemen auf Basis von Zuckerrohr signiikant höher
ist (51 %), um einen vergleichbaren Warenkorb an Produkten
zu erzeugen (Zucker und Nebenprodukte) – dies bei Treibhausgasemission in vergleichbarer Höhe. Abschließend wurden die
Limitierungen des PCFs bei der umfassenden Ermittlung der
ökologischen Nachhaltigkeit von EU-Rübenzucker untersucht.
Key words: sugar beet, white sugar, Product Carbon Footprint
(PCF), greenhouse gas (GHG) emissions, cane sugar
Schlagwörter: Zuckerrübe, Weißzucker, Treibhausgasbilanz,
Treibhausgasemissionen, Rohrzucker
1
Introduction to carbon footprints and sugar
Carbon footprints provide an estimate of the total amount of
greenhouse gases (GHG) which are emitted during the lifecycle of goods or services. Businesses, governments and other
stakeholders use carbon footprints in order to gain an understanding of the emissions of GHGs from consumer products
and also companies. Product Carbon Footprints (PCFs) can be
used for diferent purposes and that in turn inluence the level
of detail, accuracy and therefore complexity required when
conducting an assessment of the GHG impact of the product1.
According to a World Bank study (Brenton et al., 2010), carbon
1
The ILCD (International Reference Life Cycle Data System ) Handbook (2010) in
particular distinguishes 3 main goal situations (A, B, C) related to, respectively, decisions based on Life-Cycle Assessments (LCAs) at a ‘micro’ level, ‘meso-macro’ level
and for ‘accounting’ purposes.
Reprint (2012) Sugar Industry 137 | 1–17
footprint accounting methods have undergone rapid development over recent years, with no less than 16 diferent methodologies developed or undergoing development since 2007.
hese range from nationally and internationally recognized
standards such as those based on ISO, to proprietary supermarket systems which aim to satisfy an increasing market
demand for ‘climate relevant’ information along supply chains
and towards consumers (Finkbeiner, 2009).
Carbon accounting methods difer both in approach and calculation methodology. hese methodological diferences are
relected in the great variability of results from study to study
but also from data set to data set (within the same methodology). Moreover, the diferent types of GHG emissions that can
be taken into account across a product life-cycle and the choice
of what emissions are included or not (‘system boundaries’)
can also play an important role in the inal result.
For primary food products, such as sugar, the main sources
1
2
Technology/Technologie
of GHG emissions are farming, raw material processing and
transport. Land use change emissions (LUC), can also be a
significant source of emissions. GHG emissions linked to
LUC occur when a previously uncultivated area (e.g. degraded
land or forests) is converted into cultivated land (direct LUC).
A change in cultivation on existing agricultural land from
a speciic crop to another can indirectly cause a direct LUC
somewhere else (indirect LUC), if the crop being replaced is
subsequently cultivated in new and former uncultivated land.
The negative impact of this type of LUC in the increase of
emissions is largely undisputed. To agree, though, on a fair
and accurate way to calculate these emissions has proven a far
more challenging – and contentious – issue, in particular when
LUC efects are deemed to be indirect.
So far, no comprehensive attempt has been made to evaluate
the typical carbon footprint of EU beet sugar and compare the
latter with the PCF of alternative products such as imported
cane sugar or isoglucose consumed in the EU.
his paper has two main objectives: irst, to estimate the typical carbon footprint of sugar produced from sugar beet grown
in the EU based on various carbon footprinting methodologies
and secondly, to compare the derived beet sugar carbon footprint igures to the carbon footprints of its main alternative
products as consumed in the EU such as reined cane sugar
and glucose and fructose syrups derived from starch based on
publicly available data.
2
Table 1: Literature review for PCF of beet sugar, cane sugar and isoglucose
Source
Product
Region of
Region of use
production
GEMIS, version 4.2 (2004)
Sugar
GEMIS, version 4.7 (2011)
Sugar
Unknown
Unknown
Sugar, organic
British Sugar ( 2008)
Beet sugar
UK
UK
Literature review of published PCFs for sugar
In recent years, very diverse PCF numbers for sugar (cane- or
beet-based) have been published although the details of the
methodologies and the calculations behind those igures have
not always been made available. Therefore, this article will
focus mainly on published studies which provide a minimum
of details thus, allowing to attempt a meaningful classiication.
Existing publications on the Product Carbon Footprint (PCF)
of sugar can be divided into two categories: those assessing
the full life-cycle, i.e. from cultivation of sugar crops up to and
including the consumer use phase (further on called “cradle
to grave” assessments) and those assessing only a part of the
life-cycle, e.g. from cultivation up to and including the production facility of the inal product such as the sugar factory or
mill (further on called “cradle to gate” assessments). White
sugar is a ready-made ingredient used for a multiplicity of
purposes and does not lead per se to speciic GHG emissions
in the use phase. In addition to the varying emissions related
to transport to diferent sugar users (through retail shops,
restaurants or the food processing industry), the multiplicity
of possible uses for sugar also makes it very diicult to identify a single appropriate and representative model for the use
phase. Maybe for that reason, “cradle to grave” data appear to
be clearly in the minority with regards to sugar (essentially
reduced to the studies of Kägi and Wettstein, 2008; Climatop,
2010 and the GEMIS database2). A compilation of methodological details and results can be found in Table 1.
Chappert and Toury (2011) –
Cristal Union
Beet sugar
France
Not relevant
(partial PCF)
Climatop (2010a), validity
1.9.2009-30.8.2010
Climatop (2010b), validity
1.10.2010-30.9.2012
Fereday et al. (2010)
Beet sugar
Switzerland
and Germany
Switzerland
and Germany
US
Switzerland
Kägi and Wettstein (2008)
Nordic Sugar (2009)
Beet sugar
Beet sugar
Setzer / BASF (2005)
Beet sugar
Switzerland
Northern
Europe
Germany
Suiker Unie (2011)
Beet sugar
Netherlands
Climatop (2010a), validity
1.9.2009-30.8.2010
Climatop (2010a), validity
1.9.2009-30.8.2010
Climatop (2010b), validity
1.10.2010-30.9.2012
Climatop (2010b), validity
1.10.2010-30.9.2012
Fereday et al. (2010)
Cane sugar
Colombia
Not relevant
(partial PCF)
Switzerland
Cane sugar
Paraguay
Switzerland
Cane sugar
Colombia
Switzerland
Cane sugar
Paraguay
Switzerland
Cane sugar
US?
Not relevant
(partial PCF)
Hattori et al. (2008)
Cane sugar
Japan
Kägi and Wettstein (2008)
Kägi and Wettstein (2008)
Cane sugar
Cane sugar
SW Japan /
hailand
Colombia
Paraguay
Plassmann et al. (2010)
Cane sugar
Mauritius
Plassmann et al. (2010)
Cane sugar
Zambia
Rein (2010)
Cane sugar
Unknown
Not relevant
(partial PCF)
Seabra et al. (2011)
Cane sugar
Setzer / BASF (2005)
Cane sugar
Brazil CenterSouth
Brazil
Yuttiham et al. (2011)
Cane sugar
Wiltshire et al. (2009) from
Plassmann et al. (2010)
Setzer / BASF (2005)
Cane sugar
Not relevant
(partial PCF)
Not relevant
(partial PCF)
Not relevant
(partial PCF)
Not relevant
(partial PCF)
Not relevant
(partial PCF)
Setzer / BASF (2005)
Setzer / BASF (2005)
2
Beet sugar
Beet sugar
Isoglucose
from winter
wheat
Isoglucose
from US corn
Isoglucose
from US corn
Eastern
hailand
Zambia
Germany
US, dry milling process
US, wet milling process
Switzerland
Not relevant
(partial PCF)
Switzerland
Not relevant
(partial PCF)
Not relevant
(partial PCF)
Switzerland
Switzerland
Not relevant
(partial PCF)
Not relevant
(partial PCF)
Not relevant
(partial PCF)
GEMIS is a public domain software/database for eco-balancing. GEMIS was originally developed in Germany by Öko-Institut and Gesamthochschule Kassel (GhK).
Sugar Industry 137 (2012) Reprint | 1–17
Technology/Technologie
Quality
System limits
Co-products
Co-product acccounting method
Unknown
Unknown
Unknown
Unknown
White sugar
Unknown
Cultivation –
delivery to customer
Unknown
White sugar
Full life-cycle
Carbonatation lime, animal
PAS 2050
feed, surplus electricity, topsoil
Unknown
Upper heating value
Co-production of sugar and
ethanol
Unknown
Unknown
White sugar
Full life-cycle
Unknown
Unknown
Unknown
Cultivation – sugar factory
Economic value allocation (92% of emissions to sugar)
White sugar
White sugar
Full life-cycle
Cultivation – sugar factory
Molasses, beet pulp, betaine,
rainate
Molasses, surplus electricity
Unknown
White sugar
Cultivation – sugar factory
White sugar
Cultivation – sugar factory
Raw sugar
Organic raw
sugar
Raw sugar
Organic raw
sugar
Unknown
Unknown
(reined)
Raw sugar
Organic raw
sugar
Unknown
(reined)
Full life-cycle
Exhausted pulp, waste water,
Economic value allocation (94% of emissions to sugar,
of-gases, beet soil, carbonata- only pulp and molasses accounted)
tion lime, molasses
Molasses, beet pulp and carbo- Economic value allocation
natation lime
Unknown
Unknown
Full life-cycle
Unknown
Cultivation – reinery
Surplus electricity, molasses
Cultivation – reinery
Molasses, surplus electricity
Full life-cycle
Molasses (feed), ethanol,
surplus electricity
Unknown
Cultivation – port in
English Channel
LUC – port in English
Channel
Cultivation – sugar factory
Raw sugar
Cultivation – sugar factory
Raw sugar
Cultivation – sugar factory
Unknown
Cultivation – sugar factory
Unknown
Unknown
Cultivation – factory outlet
in UK
Cultivation – starch factory
Unknown
Cultivation – starch factory
Unknown
Cultivation – starch factory
Reprint (2012) Sugar Industry 137 | 1–17
Unknown
Unknown
Bagasse, molasses
None
Molasses, surplus electricity
PCF in g CO2eq kg–1
sugar
1,468
1,514
1,331
600
561
590
680
1,040
600
675
610
480
410
Unknown
340
Unknown
530–540
Unknown
450
Surplus electricity: GHG credit (height unclear);
molasses: economic value allocation; surplus electricity: GHG credit (91% of emissions allocated to sugar)
Unclear if considered at all
630
Allocation (80–85% of emissions to sugar)
Economic value allocation (91.7% of emissions to
sugar)
Not relevant
534
(only CO2?)
425
340
400
2,100
Molasses: economic value allocation
Surplus electricity: GHG credit (72% of emissions to
sugar)
GHG credit (bagasse replacing fuel oil and surplus
electricity replacing electricity from natural gas)
Economic value allocation (82% of emissions to sugar)
307
Not relevant
550
Unknown
PAS 2050
870
Bran, pulp, gluten, “Grießkleie”, “Nachmehl”
Economic value allocation (62% of emissions to
glucose)
780
Economic value allocation (84% of emissions to
glucose)
“Kleberfutter”, germ oil, gluten Economic value allocation (83% of emissions to
glucose)
640
Surplus bagasse, surplus
electricity
Bagasse, waste water, ilter
cake, molasses
None
DDGS
234
210
1,100
3
4
Technology/Technologie
2.1
‘Cradle to gate’ studies
In the category “cradle to gate”, PCF studies for beet sugar have
been published by Setzer (2005), and Fereday et al. (2010). For
beet sugar, PCF values ranged from 610 g CO2eq/kg sugar for
German sugar (Setzer, 2005) to 1040 g CO2eq/kg sugar for US
beet sugar (Fereday et al., 2010). Both studies made a comparison with other types of sugars. In particular, Setzer assessed
white beet sugar produced in Germany and used in chemical
fermentation processes and compared the results to raw sugar
produced from Brazilian cane and with isoglucose produced
from German wheat and US corn. Fereday et al. (2010) provided PCFs for beet and reined cane sugar produced in the
USA. A few European companies producing sugar from beet
have published PCF numbers in recent years although most
of the details relating to the calculations are not publicly available. herefore, those PCF numbers will not be dealt with in
this section but can nevertheless be found in Table 1.
For cane sugar far more literature on PCF is available than for
beet sugar with a broad variation of regional validity (i.e. deinition of the areas where beet and cane are cultivated and where
sugar is produced and used), system limits, process setups and
methodologies used. Figures for cane sugar vary signiicantly
from 210 g CO2eq/kg sugar for Brazilian cane raw sugar (Setzer,
2005) up to 630 g CO2eq/kg sugar for cane white sugar from
the USA (Fereday, 2010). Within that range other values have
been published: 234 g CO 2eq/kg sugar for Brazilian CenterSouth cane raw sugar (Seabra et al., 2011), 307 g CO 2eq/kg
sugar for a supposedly ‘typical’ cane growing and sugar mill
setup producing raw sugar3 (Rein, 2010) and 550 g CO2eq/kg
sugar for cane sugar (of unknown, raw or white, quality) produced in eastern Thailand (Yuttitham, 2011). For raw cane
sugar produced in South Africa, Mashoko et al. (2010) report
more than 500 g CO2eq/kg sugar4 whereas Fereday et al. (2010)
reported 630 g CO2eq/kg sugar for cane white sugar from the
USA.
Going one step further, some studies have also considered
the emissions related to the transport of cane raw sugar
for refining from the producing country up to a refining
facility in the importing country. Figures vary considerably
according to the origin of the sugar: 400 g CO 2eq/kg sugar
for imported sugar from Mauritius up to 870 g CO 2eq/kg
sugar for imported Zambian cane sugar, both delivered at a
refining outlet in the UK (Plassmann et al., 2010; Wiltshire et
al., 2009). Those studies concluded that overseas transport
3
4
5
This ‘typical’ setup is supposed to reflect a global average. Therefore a GHG credit
for surplus electricity of 150 g CO2eq/MJ is given, which means an electricity mix
containing a good share of fossil fuels. On the other hand some of the figures used
for cultivation and processing appear to be close to the situation of Brazil’s CentreSouth region, in principle, a high-efficiency sugar producing region.
The article by Mashoko et al. (2010) on South African raw sugar presents its data
in a way that can be easily misread (see for example, Rein (2011) which refers, for
that article, to a value of 364 kg CO2 ‘equivalent’/t of sugar) whereas in fact Mashoko
et al., (2010) provide separate values for CO2, CH4 and N2O and not the total CO2
equivalent. Taking into account the global warming potential (GWP) of the various
gases emitted, the total exceeds 500 g CO2 equivalent/t of raw sugar).
The PCF values provided by Hattori et al. (2008) for the imported raw material, Thai
raw sugar, before transport to Japan and refining (i.e. 118 g CO2/kg sugar), appear
strikingly low when compared to the values (550 g CO2eq/kg sugar) published in the
specific study on Thai sugar by Yuttiham et al. (2011). At this stage, it cannot be
ruled out that their data refers only to direct CO2 emissions and not to all greenhouse gases combined (expressed as CO2eq) which, if that is the case, would stress the
significant impact of N2O and CH4 emissions from cane cultivation on the final PCF
results.
had a significant impact on the PCF of imported cane sugar.
Finally, Hattori et al. (2008) provided a PCF of 534 g CO2eq/kg
sugar for raw cane sugar from Thailand transported to and
refined in Japan5.
When referring to published PCFs for cane sugar, it must be
kept in mind that direct land use change (LUC) can have a signiicant impact on those PCFs, in particular for sugar originating from tropical countries. However, emissions due to direct
LUC appear to be rarely accounted for in most of the published
PCFs for cane sugar. his is apparently partly due to lack of
data on previous and on-going conversion of forest land to
crop land (Rein, 2010). In his article about the ‘typical’ carbon
footprint of cane sugar, Rein (2010) considered direct LUC
conversion from natural vegetation to cane growing to cause
a substantial increase in calculated carbon emissions although
he did not include nor quantify that efect in his own calculations. Plassman et al. (2010) found that sugar from Zambia
delivered to a harbour in the English Channel could reach up
to 2100 g CO2eq/kg sugar if GHG emissions from direct land
use change were included, that being one of the rare articles to
actually account for that efect.
GHG emissions for glucose and fructose syrups derived from
starch (isoglucose or HFCS as it is most commonly known
in the USA) can be derived from Setzer (2005). For German
winter wheat used as raw material he reports 780 g CO2eq/kg
isoglucose whereas for the US corn-based variant, values range
from 640 g CO2eq/kg (dry milling process) to 1100 g CO2eq/kg
isoglucose (wet milling process).
2.2
“Cradle to grave” studies
“Cradle to grave” studies are deemed to include the full lifecycle of the product also including the use phase. Kägi and
Wettstein (2008) and Climatop (2010) made a cradle to grave
assessment for beet sugar from Switzerland (white sugar quality) and compared the results with cane sugar from Colombia
(raw sugar quality) and organic cane sugar from Paraguay (raw
sugar quality). he two Swiss-based studies of Kägi and Wettstein (2008) and Climatop (2010) show a varying range of
results ranging from 410–540 g CO2eq/kg sugar for imported
Colombian raw cane sugar and 340–450 g CO2eq/kg sugar for
organic raw sugar imported from Paraguay. he latest GEMIS
database version 4.7 (2011) also distinguishes between conventional sugar – GHG emissions of 1514 g CO2eq/kg sugar –
and organic sugar – GHG emissions of 1331 g CO2eq/kg sugar.
It remains unclear if these igures were calculated for beet or
cane sugar and how the calculations were carried out. It is
worth noting that the GEMIS 2011 igures (1514 g CO2eq/kg
sugar) represent an increase from previously published GEMIS
igures (GEMIS 4.2 of 2004 provided a igure of 1468 g CO2eq/kg
sugar); whereas, over the past decades – at least for EU beet
sugar – agricultural inputs (such as fertilizer application rates)
decreased whilst beet/sugar yield increased in parallel, as well
as fuel demand of sugar factories which were reduced by process optimization measures. In general terms the values published in 2008 by Kägi and Wettstein were those in the lower
range whereas the 2010 values published by Climatop represented a signiicant increase. hat was also the case for Swiss
Sugar Industry 137 (2012) Reprint | 1–17
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beet sugar whose footprint increased between 2008 and 2010,
from 590 to 680 g CO2eq/kg sugar. Both for the Swiss-based
studies and the GEMIS database it remains unclear what were
the reasons for the increase in the absolute PCF igures for
those types of sugar within a relatively short time period.
It appears from the above screening of published literature that
there is signiicant variability of PCFs for sugar. hat variability
is due to multiple factors including, but not limited to, diferences in product types and qualities, diferent geographical
scopes, diferent impacts being considered (e.g. for cane sugar
the inclusion or not of overseas transport or LUC), diferent
system boundaries (“cradle to gate” vs. “cradle to grave”), diferent factory process setups and diferent co-product accounting
methods (e.g. GHG credits from surplus electricity). In such a
complex context, it would be clearly inappropriate to simply
take those PCFs at face value and compare them with one
another without taking into account the diferent sets of methods and assumptions underlying those calculations.
3
Methodology used in this study
Within this study, “cradle to gate” PCFs of EU beet sugar were
calculated. The system limits are from cultivation of sugar
beet up to and including the sugar factory, but excluding the
packaging, distribution and use of the sugar (see Fig. 1). Processes in the background system such as the emissions related
to the production of fertilizers and fuel were included whereas
manufacturing and maintenance of machinery and infrastructure were not taken into account. he outputs from the analysed system are the following co-products: sugar, molasses,
wet pulp, pressed pulp, dried pulp with molasses, sugar factory lime (a liming fertilizer), beet soil, surplus electricity and
surplus heat. he functional unit on which PCF results are
expressed is one tonne of white sugar.
Data for sugar beet cultivation and transport emissions were
taken from the Biograce (2011) database. hese data are oicially used within the EU renewable energy directive (RED)
to assess GHG emissions associated with bioethanol from
sugar beet and serve in the present case as a generic average of
the speciic GHG emission of sugar beet cultivation. For data
related to the sugar beet transport distances and emissions
from beet sugar production, EU average igures for the sector were used. Average EU beet sugar factory emissions were
calculated based on an EU-wide study conducted by ENTEC
for the European Association of Sugar Producers (CEFS) in
2010. he data covered the period 2005–2008, which does
not fully relect the massive closure of, often less-eicient,
factories which took place throughout that period and until
the end of the last decade, as a result of the EU sugar market
reform. A base-case relecting the average emissions of EU
beet sugar production was calculated including an average
of EU beet pulp drying practices.6 Since there are sugar beet
factories either producing wet/pressed beet pulp or drying
the beet pulp, two variations of the factory setup, ‘no drying’
(scenario 1) and ‘all beet pulp is dried’ (scenario 2) were also
assessed. For details of the data used see Tables 2 to 5.
6
Based on the EU average for the period 2005–2008 that was an average production of 7% wet pulp, 31%
pressed pulp and 62% dried pulp
(source: estimate based on CEFS
(2010) for the period 2005–2008
on the basis of a standardised dry
matter content for beet pulp of, respectively, 13% (‘wet pulp’), 22%
(‘pressed pulp’) and up to 92% (‘dried
pulp’).
Reprint (2012) Sugar Industry 137 | 1–17
potential (GWP) factors used
(Source: IPCC, 2007)
GWPs (IPCC, 2007)
CO2eq
CO2
1
CH4
25
N 2O
298
Table 3: Data used for sugar beet cultivation, sugar beet transport and as
inputs of sugar factory
Unit
Sugar beet cultivation (Input)
Diesel
L ha–1 year–1
Nitrogen fertilizer
kg N ha–1 year–1
CaO fertilizer
kg ha–1 year–1
kg K2O ha–1 year–1
Potassium (K2O)
kg P2O5 ha–1 year–1
Phosphorous (P2O5)
Pesticides
kg ha–1 year–1
Seed
kg ha–1 year–1
kg N2O ha–1 year–1
Field N2O emissions
Sugar beet cultivation (Output)
Sugar beet (clean)
t ha–1 year–1
Dirt tare
Sugar beet (with tare)
Beet transport
Average distance
Transport mode
% on sugar beet
t ha–1 year–1
Spec. diesel consumption
MJ t–1 km–1
Beet sugar factory (Input)
Process steam production
Spec. fuel consumption
kWh t–1 sugar
Lime kiln operation
Spec. fuel consumption
kWh t–1 sugar
Spec. limestone consumption
t t–1 sugar
t t–1 sugar
Fuel transport
Limestone transport
Pulp drier
Spec. fuel consumption
Fig. 1: System boundaries of the analysed system
Table 2: Greenhouse warming
km
% road by truck
km
km
Amount
Source
177
120
400
135
60
1.3
6
3.27
Biograce
(2011)
68.9
8.9
75.0
45
100
0.94
1522
Biograce
(2011)
CEFS
CEFS
Assumption
Biograce
(2011)
ENTEC
(2010)
74.2
ENTEC
(2010)
0.0096 *
0.12
ENTEC
(2010)
400
**
400
**
kWh t–1 pulp dry 1370
ENTEC
substance
(2010)
* For lower heating value of 7.7 MJ kg–1 (GEMIS 4.5). ** Assumption (100%
by truck).
5
6
Technology/Technologie
Table 4: Data used for sugar factory output
Beet sugar factory (output)
Unit
Amount
Scenario 1
(drying of full amount of
beet pulp)
0.128
0.137
0.027
0.02
0
0
0.072
0.05
29.4
2.94
EU average
White sugar
Beet soil
Carbonatation lime
Molasses
Wet pulp
Pressed pulp
Dried pulp with molasses
thereof beet pulp
Net electricity export
Net steam/heat export
t t–1 sugar beet
t t–1 sugar beet
t t–1 sugar beet
t t–1 sugar beet
t t–1 sugar beet
t t–1 sugar beet
t t–1 sugar beet
t t–1 sugar beet
kWh t–1 sugar
kWh t–1 sugar
Table 5: Speciication of sugar factory outputs
Beet sugar factory (output) Dry substance
Digestible
in %
energy in
MJ kg–1 dry
substance
White sugar
100
16.8
Beet soil
65
0
Carbonatation lime
70
0
Molasses
80
12.29
Wet pulp
13
12.1
Pressed pulp
22
12.1
Dried pulp with molasses
92
12.1
0.128
0.137
0.027
0.02
0.03
0.07
0.051
0.031
29.4
2.94
Lower heating
value (LHV)
in MJ kg–1
16.92
0
0
10.4
0.0
1.6
14.5
Sugar factories produce a set of different products including, but not limited to, sugar, beet pulp, molasses and sugar
factory lime (i.e. it is a multifunctional process). In order to
establish the PCF of the product beet sugar, at irst the total
GHG emissions of the whole system were identiied and then
followed the stepwise procedure of ISO 14044 norm for emissions accounting, which can be summed up as follows:
– Step 1: Allocation should be avoided by dividing the unit
process into independent sub-processes or by expanding the
product system to include the additional functions related
to the co-products and calculating GHG credits for the coproducts (substitution method).
– Step 2: Where allocation cannot be avoided (i.e. step 1 cannot be applied or is inadequate), the inputs and outputs
Electricity
Steam / heat
Fodder cereal (barley, wheat); wheat
bran; citrus; corn gluten feed; lucerne
(alfalfa); spent grains (from breweries)
Electricity from grid
Steam/heat produced by 3rd parties
0.128
0.137
0.027
0.04
0
0.227
0
0
29.4
2.94
CEFS (2010)
CEFS (2010)
Estimate
Estimate
CEFS (2010)
CEFS (2010)
CEFS (2010)
CEFS (2010)
ENTEC (2010)
ENTEC (2010)
of the system should be partitioned between its diferent
products or functions in a way that relects the underlying
physical relationships between them.
– Step 3: Where physical relationship alone cannot be established or used as the basis for allocation, the inputs should
be allocated between the products and functions in a way
that relects other relationships between them. For example,
input and output data might be allocated between co-products in proportion to the economic value of the products.
In the present study, the authors decided to apply the most
common accounting methods across all steps (1 to 3 above) as
a way of identifying possible biases in the choice of accounting
methodologies and in order to explore the practical diiculties
and challenges associated with the implementation of some of
those accounting methods.
he irst step in the ISO hierarchy, consisting in the division
of the system into separate sub-processes, could not be implemented in order to solve the multi-functionality of the production process. System expansion (also called ‘substitution’)
was then analysed. In that context several equally adequate
substitution products could be identified for the main coproducts, which, in turn, resulted in significantly different
PCFs for sugar. his is because some of those co-products can
either be used in diferent sectors (like molasses) or – as in the
case of feed products – a group of equivalent products exists.
To show the extreme variation of results depending on the
type of substitute products selected, the authors have chosen
Table 6: Sugar factory outputs and their competing products (substitutes)
Beet sugar factory (output)
Competing products (substitutes)
Chosen substitutes for example I
White sugar
Reined cane sugar
Not relevant
Beet soil
Agricultural soil
Not accounted for
Carbonatation lime
Mineral lime fertilizer
Mineral lime fertilizer
Molasses
As feed: fodder cereal (e.g. barley),
hick juice from sugar beet
As raw material for fermentation
industry: raw, thin or thick juice; cane
molasses
Wet pulp
Fodder cereal (barley, wheat); corn
Corn whole plant for silage
whole plant for silage
Pressed pulp
Dried pulp with molasses
Source
Scenario 2
(no drying of beet pulp)
Chosen substitutes for example II
Not relevant
Not accounted for
Mineral lime fertilizer
Fodder barley
Fodder barley
Fodder barley
Dried lucerne (alfalfa)
EU average grid intensity
Not accounted for
Marginal electricity: coal
Not accounted for
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Table 7: Data used to calculate GHG credits
Unit
Mineral lime fertilizer
CaO content carbonatation lime
hick juice from sugar beet
Energy demand / surplus electricity compared to
sugar beet production
Spec. thick juice production
Substitutes for co-product credits:
– Beet soil: not accounted for
– Carbonatation lime: mineral lime fertilizer
– Wet pulp & pressed pulp: corn whole plant for silage
– Dried pulp: fodder barley
– Surplus electricity: EU average grid intensity
– Surplus heat/steam: not accounted for
Corn whole plant for silage
Diesel
Nitrogen fertilizer
CaO fertilizer
Potassium (K2O)
Phosphorous (P2O5)
Pesticides
Seed
Field N2O emissions
Corn yield
Dry substance content of corn
Digestible energy
Fodder barley
Diesel
CaO fertilizer
Nitrogen fertilizer
Potassium (K2O)
Phosphrous (P2O5)
Pesticides
Seed
Field N2O emissions
Barley yield
Digestible energy
Dried lucerne (alfalfa)
Diesel
Nitrogen fertilizer
CaO fertilizer
Potassium (K2O)
Phosphrous (P2O5)
Pesticides
Seed
Field N2O emissions
Fuel for drying (diesel)
Lucerne yield
Dry substance lucerne
Protein content lucerne
Dry substance after drying
Digestible energy
EU average grid intensity
Emission factor of grid electricity
Marginal electricity: coal
Emission factor of coal
Power plant
kg CaO kg–1
0.27
%
kg thick juice kg–1 sugar
90
1.7
L ha–1 year–1
kg N ha–1 year–1
kg ha–1 year–1
kg K2O ha–1 year–1
kg P2O5 ha–1 year–1
kg ha-–1 year–1
kg ha–1 year–1
kg N2O ha–1 year–1
t corn dry substance ha–1 year–1
%
GJ t–1 corn
105
51.7
1,600
25.8
34.5
2.4
0
0.82
7.5
35
3.7
Source
Bürcky and Märländer (2000)
Assumption
Assumption
Assumption
Biograce (2011)
Assumption
DLG Futterwerttabellen (1997)
L ha–1 year–1
kg ha–1 year–1
kg N ha–1 year–1
kg K2O ha–1 year–1
kg P2O5 ha–1 year–1
kg ha–1 year–1
kg ha–1 year–1
kg N2O kg–1 N applied
t barley ha–1 year–1
GJ t–1 barley
100
150
98
28
35
2.0
120
0.021
4.2
11.3
L ha–1 year–1
kg N ha–1 year–1
kg ha–1 year–1
kg K2O ha–1 year–1
kg P2O5 ha–1 year–1
kg ha–1 year–1
kg ha–1 year–1
kg N2O kg–1 N applied
GJ t–1 dried protein
t lucerne dry substance ha–1 year–1
%
kg raw protein t–1 dry substance
%
GJ t–1 dried lucerne
50
15
320
256
33
0
12
0.021
41.868
8.7
40
200
88
7.2
Assumption
g CO2eq kWh–1 electricity
465.1
Biograce (2011)
g CO2eq kWh–1 coal
%
400.61
40
Biograce (2011)
Assumption
two examples of ‘substitution scenarios’ based on diferent
substitutes (for details see Table 6 and Table 7). In that context, no substitute was accounted for beet soil or surplus heat
(Table 8) which, in practice, means that no emission credit was
given for those two outputs.
Reprint (2012) Sugar Industry 137 | 1–17
Amount
Assumption
Assumption
EFMA (data for EU 15, 2004/05)
Assumption
Kaltschmitt and Reinhardt (1997)
IPCC (2006)
EFMA (data for EU 15, 2004/05)
DLG-Futterwerttabellen (1997)
Hanff et al. ( 2008)
Assumption
Peyker and Degner (1996)
IPCC (2006)
COPA COGECA et.al. (2007)
Hanff et al. ( 2008)
DLG Futterwerttabellen (1997)
Additionally, PCFs of beet sugar were also calculated by allocation based on a physical criteria (step 2 of the ISO 14044
hierarchy). Four possible physical relationships could be identified and were subsequently used: mass (wet), mass (dry
substance) and energy (as digestible energy and lower heat-
7
8
Technology/Technologie
Table 8: Chosen substitutes
Co-product
Beet soil
Carbonatation lime
Molasses
Wet pulp
Pressed pulp
Dried pulp with molasses
(incl. pulp drying)
Surplus electricity
Surplus heat
Substitute chosen
Example I
Example II
Not accounted for
Mineral lime fertilizer
hick juice
Fodder barley
Corn whole plant
(for silage)
Fodder barley
Fodder barley
EU grid mix
Lucerne (alfalfa), dried
Marginal electricity
(from hard coal)
Not accounted for
ing value, LHV). Surplus electricity production was assessed
homogeneously across the four allocation scenarios through
the substitution method (using EU grid average).
For the economic allocation methodology (the lowest ranked
in the ISO hierarchy) no less than 5 diferent price references
applicable to EU beet sugar were identiied (see also Fig. 2):
(1) the EU regulatory reference price for white sugar – an
oicial EU price related to a standardised estimate of EU beet
sugar production costs, (2) the EU average market price for
bulk sugar for food uses, (3) the EU average market price for
bulk sugar for non-food uses, (4) the World market price for
white sugar – as an indication of EU sugar export prices – and
inally (5) an EU-mix price that would relect a combination
of the previous three types [(2) to (4)] of sugar prices according to the share of the diferent EU beet sugar sales (based
on public statistics for food, non-food markets and exports).
When combined with the three diferent factory settings analysed (base case, no drying of beet pulp and drying 100% of
the pulp) no less than 15 diferent PCFs for the same beet
sugar were identiied under economic allocation. All of them
are shown in the results section of this article. For co-products
other than sugar the same price was used in all variations.
3.1
Cut-of criteria, assumptions and limitations
With regard to farming operations, all N-fertilizer was
assumed to be in the form of mineral fertilizer, as there is no
publicly available igure known for the average use of organic
fertilizer (e.g. manure) in sugar beet cultivation in Europe. All
the basic inputs to sugar beet cultivation were included, that
is, seed, fertilisers, pesticides and diesel consumption for ield
work. Nitrous oxide, soil emissions (N2O, commonly known
as laughing gas) from farming were included according to
Biograce (i.e. 2.7% of applied N is emitted as N2O). Transport
of sugar beet and adherent soil was also accounted for, and it
was assumed that all transports are by 40-t truck. he emissions related to the return of empty trucks delivering beet to
the factories were also accounted for in the Biograce data.
GHG emissions linked to LUC (land use change, direct or indirect) were estimated to be negligible because all land used to
grow beet, at least in the EU, is already arable land.
With regard to factories, very small inputs were excluded. Speciically, most process chemicals used in sugar production such
as NaOH or HCl for pH correction or antifoaming agents were
assumed not to be signiicant for the overall result because
they were used only in small quantities. However, as limestone
is a processing aid used in larger amounts (approx. 2% per
tonne of beet processed), it therefore was included.7
For surplus steam, which some factories co-produce, substitutes were diicult to establish, because they depend on the
local situation. Since the resulting GHG credit for surplus
steam was expected to be small as an EU average, no GHG
credit for surplus steam was calculated. Potential emissions
from water treatment systems were, on the other hand, not
taken into account because there is insuicient data available
about the diferent types of water treatment systems in operation in EU beet sugar factories.
he emission factors of the process inputs used in the calculations are listed in Table 9.
3.2
For the supply of cane sugar to the EU the most common scenario is the production of raw cane sugar in a tropical country,
which is then transported as bulk sugar to a reinery located
within a European harbour to produce white cane sugar. However, raw cane sugar imports that are consumed as such (i.e.
raw) constitute a diferent product and moreover represent very
limited amounts out of the total amount of sugar consumed in
Europe.8 For that reason raw cane sugar as a inal product was
not considered for the purpose of this comparison. Semi-white
sugar originating directly from cane sugar mills (‘plantation
white sugar’) is not typically consumed as such in the EU and
was also not considered to be a full substitute of crystal white
sugar (from beet or cane), notably for applications such as soft
drinks and pharmaceutical products which often require very
high purity (e.g. very low levels of ash and other plant material,
even at trace levels9), very low sugar colour levels and speciic
crystal sizes among other quality requirements.10
7
Fig. 2: A selection of different prices applicable to EU beet sugar and their
evolution throughout several years. All prices are shown in EUR/t (Source:
Data from European Commission and other public sources).
Calculation of a comparable PCF for cane sugar
used for reining
8
From a procedural point of view, when calculating the PCF of actual factories, the
size of the emissions from inputs suspected to be ‘small’ may still need to be evaluated before these can be ruled out.
According to Eurostat data, imports of ‘raw cane sugar not for refining’ (code 1701
11 90) represented less than 4% of the total sugar consumed in the food market in
the EU in 2010 (Eurostat trade database accessed in September 2011).
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Table 9: Emission factors used
Unit
Cultivation (Input)
Diesel
Nitrogen fertilizer
CaO fertilizer
Potassium (K2O)
Phosphorous (P2O5)
Pesticides
Sugar beet seeds
Corn seeds
Barley seeds
Lucerne (alfalfa) seeds
Transports
Truck for dry products
Ship, ocean bulk carrier
Beet sugar factory (Input)
Fuel provision and use for process
steam production
Fuel provision and use in lime kiln
Limestone provision
Fuel provision and use in pulp drier
Cane sugar reinery (Input)
Fuel oil
Emission factor
kg CO2eq L–1
g CO2eq MJ–1
kg CO2eq kg–1
kg CO2eq kg–1
kg CO2eq kg–1
kg CO2eq kg–1
kg CO2eq kg-1
kg CO2eq kg–1
kg CO2eq kg–1
kg CO2eq kg–1
kg CO2eq kg–1
3.14
87.64
5.88
0.13
0.58
1.01
10.97
3.54
–
0.15
–
g CO2eq t–1 km–1
g CO2eq t–1 km–1
82.5
17.6
g CO2eq kWh–1
g CO2eq kWh–1
kg CO2eq t–1
286.1
414.6
11.58
g CO2eq kWh–1
303.7
Fuel mix: ENTEC (2010), emissions factors Biograce ( 2011)
Fuel mix: ENTEC 82010), emissions factors GEMIS 4.5
GEMIS 4.5 (only provision to market, no CO2 from burning,
since CO2 is precipitated in the process as CaCO3 again)
Fuel mix: ENTEC, 2010 Emissions factors Biograce ( 2011)
g CO2eq kWh–1
305.9
Biograce ( 2011)
Because raw cane sugar can be supplied from various regional
origins, two different examples were assessed: example I
(which more or less would relect import of cane sugar from
Brazil Centre-South) assumed 400 km truck transport within
the production country and 10,000 km transport by ocean
carrier to a harbour within the EU. Example II (which could
be applicable to imports of sugar from South-East Africa)
assumed only 50 km truck transport within the production
country and 5000 km transport by ocean carrier to a harbour
within the EU.
Due to the absence of an existing data set available for cane
sugar for reining in the EU (such as the ENTEC data set for
EU beet sugar), it was decided to estimate a PCF for cane sugar
used for reining in the EU based on published literature data.
For that purpose, data from Rein (2010) were used as a basis
since the latter was supposed to relect a ‘typical’ PCF for cane
sugar. It should be noted, however, that under closer examination, it appears, in particular, that some of its data relects best
performance levels in sugarcane growing and above-average
electricity exports to the grid. his assessment is particularly
relevant with regard to one major GHG emitting factor (N-fertilizer and the derived N-ield emissions) and a major source of
GHG ‘credit’ (electricity put into the public grid):
– Application rate of mineral N fertilizer is assumed to be
75 kg N/ha/a by Rein (2010) whereas Yuttiham et al. (2011)
9
10
Source
That is the case, for example, with the undesirable ‘Acid Beverage Floc’ formation in
soft drinks due to the presence of trace elements in some sugars at a level of some
parts per million (ppm). Cf. Clarke et al. (1999).
See for example van der Poel et al. (1998; p. 84, 98 and following): “Advanced processes
in the food industry and the development of new products have historically led to specific
and sensitive analytical methods to assess sugar quality. These have revealed that even a
small portion of less than 0.1% of additional non-sucrose substances in sugar affects the
quality of the sugar and its behaviour during storage and either industrial processing or
household use”.
Reprint (2012) Sugar Industry 137 | 1–17
Biograce ( 2011)
Kaltschmitt and Reinhardt (1997)
Biograce ( 2011)
Biograce ( 2011)
have recently reported – for the situation in Eastern hailand (a top-three world exporter of cane sugar) N fertilizer
application rates between 19 and 939 kg N/(ha · a) (199 kg
N/(ha · a) on average). In Australia, another top-three world
cane sugar exporter, Renouf and Wegener (2007) reported
N-application rates (urea) at similar levels [167 kg N/(ha ·a)
average in Queensland with a range between 140–223 kg
N/(ha · a)]. hose N-use levels refer only to N in urea and do
not include partial N applications though ammonium sulphate (12 kg/ha as S) or diammonium phosphate (19 kg/ha
as P). Finally, in South Africa, Mashoko et al. (2010) reported
120 kg N/(ha · a).
– When it comes to ield emissions of N2O due to N-fertilizer
application, Rein (2010) used a speciic conversion factor
(1.325% of N in nitrogen fertilizer converted to N in N2O
emissions) derived from general IPCC guidelines. Several
studies, in particular with regard to sugarcane cultivation
in Australia (Denmead et al., 2009 and Renouf and Wegener,
2007) have shown that actual N-fertilizer conversion rates
for cane growing soils can be much higher due to the climatic
conditions and some cultural practices in sub-tropical and
tropical high-rainfall regions in which sugarcane is grown.11
In the present article, for beet sugar cultivation, the authors
made use of the EU Biograce igures which are crop-speciic
and which assume that 1.718% (a higher fraction than the
default IPCC value used by Rein) of N in nitrogen fertilizer is
converted to N in N2O emissions.
11
In particular, Denmead et al. (2010) refer to values oscillating between 2.8% and 21%
of N in nitrogen fertiliser converted to N in N2O emissions for different Australian
sites compared with a default national inventory value of 1.25%. They enunciate
as possible causes the ‘climatic conditions and cultural practices in the sub-tropical
and tropical high-rainfall regions in which sugarcane is grown in Australia’ as being
conducive to rapid carbon and nitrogen cycling.
9
10
Technology/Technologie
– Although exports of surplus electricity take place – to some
extent – in some countries (see Seabra et al., 2011, for Brazil
and Hattori et al., 2008, for hailand) exports of surplus
electricity are only carried out by a certain fraction of cane
mills and only to the extent permitted by the local situation
of the mill. Rein (2010) used an average value of 20 kWh
surplus electricity/t sugarcane. Other studies (e.g. Seabra,
2011) report that in Brazil Centre-South only 100 mills –
out of a total exceeding 40012 – export electricity thus resulting in a regional average of 10.7 kWh/t sugarcane, therefore
Rein’s value seems to be high and not average.
hat PCF value for cane sugar was then adjusted by adding
the emissions related to the estimated transport distance to
a reining facility in Europe (local transport within Europe
was however set at zero km between the arrival port and the
reining installation) plus emissions of raw sugar reining into
white sugar derived from energy use data from Fereday et al.
(2010). For a detailed summary of the assumptions and data
used to estimate those emissions please see Table 10.
Despite their potential relevance, direct LUC efects were not
calculated or added to the base igures of Rein (2010) as the latter
relected a hypothetical situation not related to a speciic country
of origin. Indirect LUC efects lack, in any case, a suiciently
clear methodology to account for those and were therefore not
considered at this stage of their methodological development.
3.3
Beyond the carbon footprint of sugar: GHG and
land use eiciencies of production systems
In multi-functional processes, where the total emissions of the
analysed system are to be shared among diferent co-products,
diferent methodological choices may signiicantly inluence the
calculated PCFs and thus result in biased comparisons between
the GHG eiciency of products. An alternative approach is to
compare the land use eiciency of producing a given amount
of a product, e.g. white sugar, under alternative production
systems (e.g. beet and cane sugar) taking into account the full
set of products generated, the total GHG emitted and the total
amount of land required by each production system.
In the case of beet and cane sugar, though, the two systems do
not produce the same kind of products and/or not in the same
amounts. Hence, the cane production system will typically gen-
Table 10: Data used to calculate PCF of cane sugar delivered to EU
Unit
Amount
Example I
Example II
307
Cane sugar production
kg CO2eq t–1
sugar
Fraction of cultivation / cane
transport / mill
%
72 / 5 / 23
Sugar transport to harbour
km
100
400
Transport mode
Truck
Sugar transport to EU harbour
km
5,000
10,000
Transport mode
Ship
Sugar transport from the harbour
to EU reinery
km
0
Transport mode
Truck
794
Spec. fuel consumption of reinery
kWh t–1
sugar
Fuel used
–
Fuel oil
erate signiicant amounts of sugar, molasses and surplus electricity (the latter obtained by burning the cane ibre, bagasse)
whereas a typical beet production system will also produce,
in addition to sugar, signiicant amounts of animal feed (beet
pulp) and lime fertiliser (carbonatation lime) correlated with
a lower production of surplus electricity. In order to make a
valid comparison, the authors created two sets of ‘equivalent’
production systems (based on two diferent possible substitutes for beet pulp) to compensate for those outputs produced
in greater amounts by one system or the other (see Fig. 3).13
his system comparison makes it possible to determine overall
GHG and land use eiciencies of both production systems.
Fig. 3: Diagram representing the concept of a comparison between beet
and cane production systems on the basis of the amount of land required
to produce an equivalent set of products.
4
4.1
Results
Total emissions of the deined (beet) system
he overall system emissions for sugar beet cultivation, sugar
beet transport and sugar production are shown in Table 11.
About 32% of these emissions are associated with sugar beet
cultivation, 4% with sugar beet transport and the remaining
part, about 64%, with sugar beet processing in the sugar factory (see Fig. 4). Nearly 50% of the overall GHG emissions are
due to the production of steam for the sugar factory process.
Compared with the EU average case described above, total
emissions decreased by 11% under scenario 1 (i.e. no drying
of sugar beet pulp) whereas they increased by about 7% when
assuming drying of the full amount of beet pulp produced
(scenario 2) (see Table 11).
Within sugar beet cultivation the main
contributors to GHG emissions were
N2O ield emissions (40%), nitrogen ferSource
tilizer production (29%) and diesel use
(23%) (see Fig. 5).
Rein (2010)
Rein (2010)
Assumption
Assumption
Assumption
Assumption
Assumption
Assumption
Fereday et al. (2010)
Assumption
12
13
FranceAgriMer (2011) p. 89.
Example I (Centre-South Brazil): raw cane sugar
transport to harbour (400 km) and overseas transport by ship (10,000 km). Equivalent products (option [a]): barley (for wet and pressed sugar beet pulp)
and dried lucerne/alfalfa (for dried sugar beet pulp
with molasses).
Example II (South-East Africa): raw cane sugar transport to harbour (50 km) and overseas transport by
ship (5000 km). Equivalent products (option [b]):
corn, whole plant (for wet and pressed sugar beet
pulp) and barley (for dried sugar beet pulp with molasses).
Sugar Industry 137 (2012) Reprint | 1–17
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Table 11: System GHG emissions of sugar beet cultivation and beet sugar
production in kg CO2eq t–1 sugar (before GHG credits/allocation of emissions)
EU average
Beet cultivation
Beet transport
Sugar factory
– process steam production
– lime kiln operation
– drying of sugar beet pulp
Total
Fig. 4: Sugar beet growing, transport and processing: origin of GHG
emissions in CO2eq
Fig. 5: Sugar beet cultivation: origin of GHG emissions in CO2eq
279.8
31.7
435.5
36.6
101.1
884.5
Scenario no
Scenario full
drying of beet drying of beet
pulp
pulp
279.8
279.8
31.7
31.7
435.5
36.6
783.5
435.5
36.6
163.0
946.5
examples was mainly linked to the choice of diferent substitute products for dried beet pulp and the amount of GHG
credits associated with that choice. Hence, assuming fodder
barley as a substitute (example I) this resulted in a GHG credit
of 151 kg CO2eq/t sugar, whilst assuming that the substitute
was dried lucerne (alfalfa) (example II) this resulted in a GHG
credit of 434,3 kg CO2eq/t sugar. Among the various physical allocation methods, the allocation based on (wet) mass
systematically resulted in the lowest PCF for white sugar
(followed closely by allocation based on dry matter) whereas
energy allocation methods provided the highest PCF range
based on physical allocation methods.
Economic allocation, on the other hand, resulted in no less than 5
diferent PCFs for each scenario according to the diferent prices
for sugar chosen. Economic allocation methods resulted, in general, in the highest average ranges of PCFs for white sugar. hat is
explained by the generally larger share of
value captured by sugar compared to the
other co-products of the analysed system.
he details of each of the ifteen combinations found are shown in Figure 7.
Table 14 summarises the range of PCF
results for EU beet sugar obtained
across all the methods analysed including both the EU average case and the
two alternative scenarios considered for
the handling of beet pulp.
5
Discussion of beet sugar
results and comparison
with other products and
production systems
Using the preferred methodology of ISO
EN 14044:2006 for co-product accounting (substitution) requires making
some assumptions about the products
replaced on the market by the co-products. It is not unusual
Fig. 6: PCF of white sugar from beet (EU average and 2 different beet pulp drying scenarios)
according to the substitution and physical allocation methods (the details of the background data
used are provided in Tables 12 and 13).
4.2
PCF of EU beet sugar
Based on the various GHG accounting methods, about a dozen
diferent PCFs for white sugar under each of the beet pulp
drying scenarios considered were obtained. Roughly half of
the PCFs obtained corresponded to substitution and physical
allocation methods as shown in Figure 6.
he large diference observed between the two substitution
Reprint (2012) Sugar Industry 137 | 1–17
Table 14: Ranges of PCF results for EU beet sugar obtained across all methods
PCF range white sugar in kg CO2eq t–1 sugar
EU average case
Scenario 1 (‘no pulp drying’)
Scenario 2 (‘all pulp dried’)
242–748
176–681
311–789
11
12
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Table 12: GHG credits and allocation factors (for physical allocation) resulting from calculation
Allocation factor [–]
Substitution credit in kg CO2eq t–1 sugar
Product
Example I
Example II
Mass
Dry substance mass Digestible energy
EU average
White sugar
n.a.
0.28
0.40
0.68
Beet soil
Not accounted for
0.30
0.28
0
Carbonatation lime
7.4
0.06
0.06
0
Molasses
43.6
52.2
0.04
0.05
0.06
Wet pulp
4.8
11.2
0.06
0.01
0.01
Pressed pulp
21.3
49.8
0.15
0.05
0.06
Dried pulp with molasses
151.0
434.3
0.11
0.15
0.18
Electricity
13.7
29.5
Substitution method applied
Steam / heat
Not accounted for
Not accounted for
Total
241.8
584.5
Scenario drying of full amount of beet pulp
White sugar
n.a.
0.33
0.40
0.68
Beet soil
Not accounted for
0.36
0.28
0
Carbonatation lime
7.4
0.07
0.06
0
Molasses
45.5
52.2
0.05
0.05
0.06
Wet pulp
n.a.
n.a.
n.a.
n.a.
n.a.
Pressed pulp
n.a.
n.a.
n.a.
n.a.
n.a.
Dried pulp with molasses
212
609.9
0.19
0.21
0.25
Electricity
13.7
29.5
Substitution method applied
Steam / heat
Not accounted for
Not accounted for
Total
278.6
699
Scenario no drying of beet pulp
White sugar
n.a.
0.23
0.40
0.68
Beet soil
Not accounted for
0.25
0.28
0
Carbonatation lime
7.4
0.05
0.06
0
Molasses
88.2
104.5
0.07
0.10
0.13
Wet pulp
n.a.
n.a.
n.a.
n.a.
n.a.
Pressed pulp
68.7
160.6
0.16
0.19
0.12
Dried pulp with molasses
n.a.
n.a.
n.a.
n.a.
n.a.
Electricity
13.7
29.5
Substitution method applied
Steam / heat
Not accounted for
Not accounted for
Total
178
302
Table 13: Allocation factors (for economic allocation) resulting from calculation
Allocation factor for sugar [–]
EU white reference
EU quota white sugar
EU industrial sugar
price
EU average (total system GHG emission: 885 kg CO2eq t–1 sugar)
Average 2008
0.87
0.87
0.75
Average 2009
0.85
0.86
0.78
Average 2010
0.78
0.80
0.74
Average 2008–10
0.83
0.85
0.76
Scenario no drying of beet pulp (total system GHG emission: 783 kg CO2eq t–1 sugar)
Average 2008
0.88
0.87
0.76
Average 2009
0.86
0.87
0.79
Average 2010
0.84
0.86
0.81
Average 2008–10
0.86
0.87
0.79
Scenario drying of full amount of beet pulp (total system GHG emission: 946 kg CO2eq t–1 sugar)
Average 2008
0.87
0.86
0.74
Average 2009
0.85
0.86
0.77
Average 2010
0.75
0.78
0.71
Average 2008–10
0.82
0.83
0.74
that more than one equivalent product exists, thus allowing
for diferent choices to be made. Within this paper only two
examples with sets of possible substitutes were assessed, but
this revealed that the result was extremely sensitive to those
choices. For the substitution examples calculated, the PCF of
white sugar from sugar beet (EU average case) ranged from
Lower heating value
0.67
0
0
0.06
0
0.03
0.23
0.63
0
0
0.06
n.a.
n.a.
0.30
0.74
0
0
0.14
n.a.
0.16
n.a.
“EU-mix” price
World white price
(London #5 ICE)
0.86
0.85
0.80
0.83
0.73
0.80
0.80
0.78
0.86
0.86
0.86
0.86
0.74
0.81
0.86
0.80
0.85
0.84
0.78
0.82
0.72
0.79
0.78
0.76
300 to 643 kg CO2eq/t sugar. It has to be assumed that with different assumptions diferent results would also be obtained.
Switching to physical allocation methods also provided a large
and similar range of results (242–595 kg CO2eq/t sugar for the
EU average case). However, it was observed that for each physical allocation method (based on mass or energy) there were
Sugar Industry 137 (2012) Reprint | 1–17
Technology/Technologie
Fig. 7: PCF of white sugar from beet (EU average and 2 different beet pulp drying scenarios)
according to the economic value allocation method (based on three-year average prices between
2008 and 2010). For a breakdown of results per year, please refer to Figure 8.
based on physical relationships (range
from 645–771 kg CO2eq/t sugar for the
EU average case). Economic allocation
thus added further complexity as the
result was found to vary significantly
with time and due to the wide range of
sugar prices that can be used (that is
especially the case for products which
can be equally sold to diferent markets
with diferent prices as it is the case for
the EU sugar market regime). Finally,
this method requires some caution, in
particular when information is communicated to third parties in a detailed
and transparent manner, because it may
allow the calculation of average company prices for sugar backwards from
the communicated igures.
5.1
Comparison of EU beet
sugar PCFs with competing
products
5.1.1 Cane sugar
he GHG emissions from cane cultivation and raw cane sugar production of
307 kg CO2eq/t raw sugar published by
Rein (2010) were used as a basis for the
estimated PCF of raw cane sugar for
reining in the EU before transport to
the EU. After adjusting that figure to
account for transport and refining in
Europe, the resulting PCFs were 760 kg
CO 2eq/t white sugar (example I: sugar
Fig. 8: EU average for PCF for white sugar from beet sugar when using allocation based on
from Centre-South Brazil) and 642 kg
economic value of the co-products. Price averages for years 2008, 2009 and 2010
CO2eq/t white sugar (example II: sugar
from South-East Africa). his means, in
practice, that raw sugar transport to the
co-products which were not, in principle, allocated any share
EU and the reining of cane raw sugar have a signiicant impact
of GHG emissions (e.g. electricity has no mass or contains no
on the PCF of imported cane sugar reined in the EU. he reinenergy expressed as digestible energy or lower heating value;
ing emissions represent the main addition (+243 kg CO2eq/t
white sugar), although the overseas transport also adds a sigthe amount of digestible energy or lower heating value for
nificant amount of emissions, between 14 and 23% of the
beet soil or carbonatation lime is zero). his phenomenon was
total PCF (+88 to +176 kg CO2eq/t white sugar) depending on
partially solved in the calculations by accounting for surplus
the distance.14 Although these PCF-figures reflect just two
electricity via the substitution method. Finally, beet soil was
representative examples, it can be concluded that cane sugar
found to have a signiicant impact on mass-based allocation
reined within the EU has a PCF range (642–760 kg CO2eq/t
methods, accounting for about 30% of the total emissions
sugar) which is on average higher than the total PCF range for
that were allocated to this co-product. Beet soil is, however,
EU beet sugar (242–771 kg CO2eq/t sugar) but otherwise, it is
a relatively unproductive input that any eicient beet sugar
equivalent to the highest estimated range for beet sugar (645–
production system should try to minimise to as large an extent
771 kg CO2eq/t sugar) based on economic value allocation.
as possible. he use of mass-based methods for beet sugar proOn the other hand, it should be recalled that there are indicaduction – where beet soil is accounted for – can thus lead to
tions that the PCF for cane sugar calculated by Rein (2010)
the paradox that an ineicient soil prevention system will lead
is, at least with regard to some aspects, not a conservative
to a better performing PCF for sugar.
estimate but representative of some of the best practices in
Economic value allocation, the least preferable option according to EN ISO 14044:2006 – delivered, on the other hand,
significantly higher PCF results for white beet sugar than
14
For further background data see Table 16.
those obtained with the substitution method or by allocation
Reprint (2012) Sugar Industry 137 | 1–17
13
14
Technology/Technologie
the production of cane sugar. It was also observed that the
estimated emissions value for reining emissions used in this
article corresponds to the lower end of the reining emissions
range found in the literature (–7% versus Fereday et al, 2010;
–23% versus Hattori et al., 2008).
It should also be noted that direct land use changes were not
accounted for in the PCF of cane sugar estimated in this study
whereas for EU beet sugar the impact is estimated to be neutral. In fact due to the reform of the EU sugar market regime,
the EU turned, during the last decade, from being a net
exporter to being a net importer of sugar. Accordingly, during
the same period, the cultivation area for sugar beet has been
reduced by around 0.5 mn ha, about 25% of the total, letting
that area free for other uses, be it cultivation of other crops or
nature conservation purposes (CIBE/CEFS, 2010). In the case
of imported cane sugar, Plassmann et al. (2010) showed that
LUC can be an issue for cane sugar cultivation where it can
have an enormous impact on the resulting PCF of cane sugar
(e.g. for Zambian sugar, 400 kg CO2eq/t sugar without LUC,
and 2100 kg CO2eq/t sugar including land use change). Based
on that example it is obvious that the actual PCF of imported
cane sugar can be signiicantly higher than the PCF of domestic sugar produced from EU sugar beet.
5.1.2 Glucose and fructose syrups derived from starch
(isoglucose / HFCS)
The only PCFs for glucose and fructose syrups that could be
obtained from publicly available sources are “cradle to gate” igures using German wheat and US corn as feedstocks to produce
isoglucose (Setzer, 2005). he resulting PCFs have a range of 640
to 1100 kg CO2eq/t sugar equivalent. Due to the restricted information available about the methodology used to obtain those
PCFs it is even more diicult to infer a valid conclusion when
comparing these igures with the PCF for beet sugar than when
doing so with imported cane sugar. At this stage, it can only be
observed that the average PCF range for those syrups indicates
signiicantly higher carbon footprint igures than the calculated
range of PCFs for EU beet sugar, with only a partial common zone
around the extremes of each PCF range (the highest part of the
PCF range for beet sugar and the lowest one for starch syrups).
5.2
Comparison of GHG and land use eiciencies of
beet and cane sugar production systems
Based on an initial plot of land of 1 ha it was estimated an
identical production of 8.8 t of sugar from either beet or cane.
his was done only for the purpose of having a balanced comparison between two theoretical beet and cane systems. Actual
average EU beet sugar extraction yields are in reality far better than the hypothesis used here.15 Different co-products
are created in diferent amounts in both cane and beet sugar
production systems (e.g. more molasses and electricity in the
cane system and more animal feed and lime fertilizer in the
beet system). In order to make a valid comparison, two equivalent production systems were re-created by compensating (in
terms of land and GHG emissions) for those outputs produced
in greater amounts by one system or the other. he products
taken into consideration as well as the results of that comparison of equivalent systems are provided in Table 15.
From the above analysis it appears that the total direct emissions of both cane and beet sugar systems are similar and
comparable but a very signiicant amount of additional land
(51% more) is required for cane production systems to fully
replace beet sugar ones, in particular due to the need for cane
production systems to compensate for the animal feed (beet
pulp) produced in the beet sugar system (see Fig. 9).
Currently about 85% of EU sugar needs (~16 mn t) are covered
by locally produced beet sugar and the balance is supplied
Fig. 9: A comparison of the land use efficiency of two equivalent beet
and cane systems
15
The actual yield for the EU is about 10.6 t sugar/ha (5-year average for the period
2006–2011. Source: CEFS, 2011)
Table 15: Products taken into consideration as well as the results of that comparison of equivalent systems
Beet (EU average case)
Cane (Rein, 2010)
Additional land required /
CO2eq emitted (beet)
Sugar yield
Animal feed
Electricity
Liming fertilizer
Molasses
Total system (equivalent) emissions
Total system (equivalent) land use
Additional land required /
CO2eq emitted (cane)
8.8 t/ha
1.9 t (wet pulp)
4.9 t (pressed)
3.5 t (dried and molassed)
259 kWh
8.8 t/ha
–
–
–
–
0.9 – 1 ha
1556 – 4355 kg CO2eq
3465 kWh
–
1.9 t
1.4 t
Not leaving system
2.8 t
1491 kg CO2eq
(EU-electricity mix)
–
0.3 ha of barley
464 kg CO2eq
9731 kg CO2eq
1.29 ha
65 kg CO2eq
–
10,236 kgCO2eq (average)
[range: 8323 – 12150 kg
CO2eq]
1.95 ha (average)
[range: 1.9 – 2.0 ha]
Sugar Industry 137 (2012) Reprint | 1–17
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Table 16: GHG emission for provision of cane sugar to EU in kg CO2eq t–1
reined cane sugar
Cane cultivation
Cane transport
Cane sugar factory
Road transport to harbour
Ship transport to EU
Road transport to reinery
Reining
Total
Example I
222
16
70
33
176
0
243
760
Example II
222
16
70
4
88
0
243
642
from imports of cane sugar. he above indings therefore suggest that, in the future, an eventual shift towards a larger substitution of EU beet sugar production with cane sugar imports
into the EU will put further pressure on the global demand for
arable land. hat increased demand could, in addition, increase
the risk of land use change emissions since most uncultivated
land types, be it grassland, savannah or forest land have a
much higher carbon stock than agricultural land. On the other
hand, an increased supply of EU beet sugar in the EU market
would decrease the pressure on the global demand for land
and liberate land to supply the increasing demand for food and
feed linked to the rising global population.
6
Conclusions
he calculations made to obtain the PCF of white sugar from
sugar beet have revealed that the results are extremely sensitive to methodological choices and therefore it may be diicult
to compare the actual performance of sugar products with
regard to GHG emissions via a direct comparison of published
PCFs.
he PCF range for beet white sugar (based on the EU average
case) was 300–643 kg CO2eq/t sugar when using the substitution method, which is the preferred method for co-product
accounting according to ISO EN 14044:2006. he second preference according to this standard (allocation based on physical
relationship) delivered a similar range of 242–595 kg CO2eq/t
sugar whilst the least preferred option according to the ISO
hierarchy (economic value allocation) delivered a range of
645–771 kg CO2eq/t sugar. he total PCF range across all methods was therefore 242 to 771 kg CO2eq/t sugar from sugar beet.
The results for substitution and economic value allocation
shown in this study relect only some of the possible examples
of PCFs that can be calculated for EU beet sugar. Using the
substitution approach required making assumptions about
the most suitable substitute products. he wide diference in
results observed from the two analysed examples of substitution indicates that diferent operator’s choices and assumptions will have a signiicant impact on the results. his in turn,
can lead to diferences in PCFs for beet sugar producers not
relecting the actual improvements in product performance
but simply diferent substitution choices. When calculating
PCFs for the EU average case, economic allocation was found
to be the allocation methodology more open to a multiplicity
of results (from the same dataset) due only to diferent choices
being made by diferent operators. he latter also raised other
Reprint (2012) Sugar Industry 137 | 1–17
issues such as the complexity of its implementation (multiplicity of markets/prices for EU sugar, asymmetrical changes
in the prices of sugar and co-products) and the conidentiality
of companies’ price data when PCFs are conducted at company
level.
Physical allocation methods were found to be more constant
and limited in number although some other challenges had
to be overcome. Indeed, since physical allocation methods
cannot be applied to some beet sugar co-products (notably
surplus electricity/heat and ‘sugar factory lime’) they need to
be combined with the substitution method (in a similar way as
done in the EU Renewable Energy Directive). A method leading to conservative estimates of the PCF of beet sugar would
be to use substitution with exactly defined substitutes for
surplus electricity (e.g. national/regional grid GHG intensity),
surplus heat/steam (e.g. heat/steam related emissions from a
natural gas boiler) and ‘sugar factory lime’/carbonatation lime
(e.g. mineral lime fertilizer of equivalent grade and quality).
Due to the presence of wet products among the range of possible co-products, mass allocation (on wet basis) was found
to distort the obtained results signiicantly and would not be
recommended to calculate the PCF of beet sugar. Beet soil was
found to have a signiicant impact on mass-based allocation
methods, accounting for about 30% of the total emissions that
were allocated to this co-product. Beet soil is, however, a relatively unproductive input that any eicient beet sugar production system should try to minimise to the largest extent possible. he use of mass-based allocation methods to calculate
PCFs for beet sugar production – when beet soil is accounted
for as a co-product – can thus lead to the paradox that an ineficient soil prevention system will lead to a better performing
PCF for sugar. For that reason mass allocation methods would
not be recommended in those circumstances where beet soil
is also accounted for. Allocation methods based on energy
(digestible energy or lower heating value) seemed to be, under
the scope of present analysis, adequate candidate methodologies to account for the emissions of EU beet sugar production
systems, such as the one considered in the present study.
Finally it should be recalled that data used for beet sugar factories represent the EU situation in 2005–2008. Meanwhile –
due to the reform of the EU sugar market regime – many of the
least eicient factories have been closed down, whereas beet
cultivation and beet sugar production have been concentrated
in the most productive sites and regions. herefore it has to be
assumed that the current EU average PCF range for EU beet
sugar would be lower than the one calculated in this study.
For cane raw sugar imported and refined in the EU it was
found that the PCF range (642–760 kg CO2eq/t sugar) is generally higher than the PCF range for EU beet sugar (242–771 kg
CO 2eq/t sugar) if not equivalent to the highest estimated
range for beet sugar (645–771 kg CO 2eq/t sugar, based on
economic allocation). he estimated range for cane sugar does
not account however, for direct LUC efects, which can have a
signiicant impact by increasing the PCF igures for sugarcane.
According to the available data, the PCF range of glucose and
fructose starch syrups, based on a study of isoglucose produced either from European wheat or US corn (640 to 1100 kg
CO2eq/t sugar equivalent), appeared to be higher than the PCF
range of EU beet sugar.
15
16
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7
Beyond PCFs
PCFs are not necessarily indicators of overall environmental
sustainability of a product. This is based on the fact that
carbon footprints focus on one sole ecological impact: climate impact. Water requirements for example, although
not dealt with in this article, also vary strikingly between
crops, with sugar beet requiring, for example, half the water
needed to grow sugarcane (Gerbens-Leenes et al., 2006).
Other relevant (agro-)ecological aspects are not reflected at
all in carbon footprint figures. Sugar beet, for example, is a
key rotational crop for farmers in the EU. Grown in the same
field only every three to five years, it breaks up the common
cereal-based crop-rotations. The resulting cereal yield after
beet is 10–20% higher than after two successive years of
cereals (CIBE/CEFS, 2010). Because sugar beet is not a host
to pests or diseases which generally affect combinable crops,
the cultivation of sugar beet as a break crop also reduces
the level of weeds, diseases and pests on a given land and
therefore reduces the overall amount of pesticides applied
on the farm.
Besides methodological challenges for the calculation of PCFs
for beet sugar, further year-on-year variability of results is
to be expected due to single external factors (e.g. weather
conditions) afecting the PCFs’ values independently of actual
changes in the relative environmental performance of speciic
farmers or raw material processors. he use of PCFs at consumer level – as a tool to guide consumers’ purchase decisions
towards more environmentally sustainable choices within the
sugars category of products – appears, in the light of the above
indings with regard to the uncertainty and variability of calculations, to be a signiicant challenge.
Furthermore, although greenhouse gas (GHG) accounting
using a life-cycle approach is useful for understanding the
impact of a product or a service with respect to climate change,
the suitability of PCFs for comparing the climate performance
of diferent products is questionable in particular, in light of
the results obtained with the comparison of entire productions systems for beet and cane sugar consumed in the EU.
Indeed, the comparison of production systems for beet and
cane sugar revealed, that PCFs alone do not provide the full
GHG and land use eiciency picture. he ecological impact
indicator “land use (efficiency)” is typically assessed separately from the indicator “GHG emission / PCF”. However,
not accounting for land use eiciency (i.e. the amount of land
needed to provide a certain amount of goods) when deciding if
a product is more climate-friendly than another (i.e. just doing
so based on PCFs) could push for greater consumption of certain products while leading to an increased global demand for
land. his in turn would increase the pressure to change the
land use of previously non-cultivated land with the result of
increased global GHG emissions.
In particular, the comparison of beet and cane sugar production systems showed that, in order to supply the EU market
with sugar and its related co-products (notably animal feed),
the demand for land would be signiicantly greater in the case
of increased supplies from cane sugar whereas direct GHG
emissions would remain similar for both cane and beet sugar
production systems.
Acknowledgements
he authors would like to thank A. Papagrigoraki for her support in the preparation and editing of this article.
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Reprint (2012) Sugar Industry 137 | 1–17
L’empreinte carbone du sucre de betterave de l’U.E.
(Résumé)
Les calculs effectués pour obtenir le bilan CO2 (ou le PCF:
produits à empreinte Carbone) du sucre blanc de l’U.E. provenant de betteraves ont montré que les résultats sont extrêmement sensibles aux choix méthodologiques. Cet article fournit
quelques recommandations à cet égard. Une comparaison
entre du sucre de l’U.E. et deux sucres bruts de canne importés
et rainés en U.E. a montré que la gamme de l’empreinte du
sucre de canne importé et rainé est, en moyenne, comparable, si pas plus élevée (642–760 kg CO2eq/t de sucre) que dans
la gamme, déterminée par la même méthode dans le sucre de
betterave de l’U.E. (242–771 kg CO2eq/t de sucre). Une revue
de la littérature publiée a montré, d’une part, que les émissions pour le sucre de canne peuvent être considérables à la
suite de changements dans l’utilisation du sol, mais sont rarement prises en considération et, d’autre part, que le transport
outre-mer et le rainage ajoutent une quantité importante
d’émissions au PCF du sucre de canne importé dans l’U.E. De
la comparaison de l’eicacité de l’utilisation des sols entre les
diférents systèmes de production, on peut conclure qu’il faut
signiicativement plus de sol (51 %) pour la canne pour obtenir une quantité équivalente de produits (sucre et coproduits)
avec une quantité équivalente d’émissions de GES (gaz à efet
de serre). Enfin, les limitations de PCFs comme outil pour
évaluer pour évaluer la durabilité environnementale globale du
sucre de betteraves de l’U.E. ont été aussi analysés.
El balance de los gases de invernadero de azúcar de remolacha de la UE (Resumen)
Cálculos del balance de CO2 (Product Carbon Footprint, PCF)
de azúcar blanco de remolachas de la UE mostraron que el resultado depende extremamente de la metodología seleccionada. Es
por esto que en este artículo se presentan varias recomendaciones de metodología. El balance de CO2 de azúcar de remolacha
de la UE (valor medio) se comparó con dos ejemplos de azúcar
crudo importado y reinado en la UE. El balance de CO2 del azúcar importado y reinado, en promedio, fue similar hasta mayor
(642–760 kg CO2eq/t azúcar) que el balance de CO2 del azúcar
producido y reinado directamente en la UE (242–771 kg CO2eq/t
azúcar). Un análisis de las publicaciones al respecto mostró, por
uno, que las emisiones, originadas de cambios del uso de campos,
pueden ser considerables pero normalmente no se las toma en
cuenta, y, por otro, que el transporte de ultramar y la reinación
producen mayores valores de CO2 del azúcar importado. Una
comparación de la eicacia del aprovechamiento de áreas cultivados con caña de azúcar y con remolachas azucareras mostró que
para el cultivo de caña de azúcar, la producción de azúcar y de subproductos se requiere un poco más área (51 %), pero se obtiene
la misma emisión de gas invernadero como con la producción de
remolachas azucareras. Finalmente se estudiaron la limitaciones
del balance de CO2 como instrumento para la determinación de la
persistencia ecológica de azúcar de remolacha de la UE.
Author’s addresses: Ingo Klenk, Südzucker AG, Germany;
Birgit Landquist, Nordic Sugar, Denmark; Oscar Ruiz De Imaña,
Deputy Director-General, CEFS (Comité Européen des Fabricants de Sucre), Av. de Tervuren 182, 1150 Brussels, Belgium;
e-mail: [email protected]
17